It sounds like the sort of thing that only happens in sitcoms, but the "dine and dash" is becoming an increasing problem for cafes and restaurants.

Almost a quarter of Wellington restaurants say they have noticed more diners fleeing, or trying to flee, without paying in the past year.

A Restaurant Association survey last month found 15 per cent of restaurant owners said they had noticed more people leaving or trying to leave without paying. In Wellington, the figure was 23 per cent.

Warren Johnson, owner of Ngaio's Cafe Villa, recently took the "name and shame" approach after a couple dressed in Tawa Rugby Club clothing did a runner - he wrote identifying details on the cafe's blackboard, with the words "We know you did it".

"A couple came in for coffee and scones," he said. "I spotted them sticking out like dogs' balls, so to speak, said, ‘Keep an eye on them'. One of the front-of-house staff turned their back for a moment and they were gone.

"I put a thing on [the blackboard] saying, ‘we know you did it'. We still laugh about this couple. It was a $15 bill and I reckon we've had $15 of laughs."

Nonetheless, he said he trusted his regular customers absolutely. Once, the cafe eftpos machine broke down and more than $600 of payments had to be put off "until the next time".

"Every cent was paid during the next four days."

So why do some people run the risk of getting caught? Is it desperation to save money, or is it thrillseeking?

A Nelson cafe owner, who has a large garden area, said most people who did not pay were probably just being absent-minded.

However, it had had the occasional genuine runner. "Once they have done the runner there is not a lot you can do, which is infuriating. We see it as a risk, like retail shoplifting - theft by another name."

A Queenstown restaurant said it had noticed "dine and dash" had become a growing problem - especially in outdoor seating areas. If staff caught the offenders, they usually said they had simply forgotten.

"Our gut feeling is that some people consider it sporting to take the risk, and if apprehended use this answer, which we can't do anything about."

About 15 per cent of those surveyed said dine and dash had become more common, while 50 per cent said it had stayed at the same level. In general, the increase was by one to five dashers a month.

THE STAFF STORY

Nelson cafe owner: "In most cases people come back or ring the next day, deeply embarrassed, as they wandered off before settling up. Our staff try to be extra vigilant with outside tables, but we have had the odd genuine runner. We try to get names and phone numbers but walk-ins often do not give these details."

Wellington restaurant owner: "We have a tab card system where we swap a credit card for a tab card, so it's not really an issue for us. If anyone does walk out, we charge their credit card."

Another Wellington owner: "We have changed our table service now so we are going to have to watch and make sure that it doesn't become a problem."

Auckland restaurant owner: "It's never happened at our restaurant, but we are very aware of the possibility, especially on outside tables. It used to be much worse [10 years ago] in my experience. That was in Mission Bay and on the Viaduct where I worked. All ages, all types, young, old, families . . ."

Queenstown restaurant owner: "A good way of saving money if you are away for several weeks."